Thermosetting resin, cured product thereof, and thermosetting composition

Abstract

The present invention provides a thermosetting resin which has both dielectric properties and a glass transition temperature and has a low melt viscosity. A thermosetting resin according to an embodiment is a linear copolymer and has a repeating unit corresponding to a monovinyl aromatic compound, a repeating unit corresponding to a divinyl aromatic compound, and a repeating unit corresponding to an aromatic ring condensed cyclic olefin compound.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to a thermosetting resin, a cured product thereof, and a thermosetting composition containing the thermosetting resin. BACKGROUND

[0002] In recent years, miniaturization and high performance of electronic devices are progressing, and the required properties of various materials used in conjunction therewith are increasing. For example, a printed board material that can cope with low dielectric loss tangent for high frequency communication is required.

[0003] In Patent Literature 1, as a thermosetting resin composition excellent in dielectric properties, heat resistance, adhesion, and moisture resistance, a thermosetting resin composition containing a copolymer containing a calyxene structure unit and a hydroxystyrene structure unit, a compound having at least two epoxy groups in one molecule, and a curing agent is disclosed. In Patent Literature 1, as a specific example of the copolymer, a copolymer of styrene, p-t-butoxy styrene, divinylbenzene, and calyxene, which has a branched chain, is disclosed.

[0004] In Patent Literature 2, as a copolymer for providing a curable composition excellent in heat resistance, compatibility, dielectric properties, moisture heat reliability, and heat oxidation deterioration resistance, a copolymer containing a structure unit derived from a divinyl aromatic compound, a structure unit derived from a monovinyl aromatic compound, and a structure unit derived from a cyclic olefin compound is disclosed. In Patent Literature 2, since the copolymer is obtained by polymerizing a mixed solution of a divinyl aromatic compound, a monovinyl aromatic compound, and a cyclic olefin compound, the obtained copolymer has a branched chain.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Laid-Open No. 2001-192539

[0008] Patent Literature 2: Japanese Patent Laid-Open No. 2018-039995 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The existing thermosetting resin is not necessarily satisfactory in terms of dielectric properties, and even if it is excellent in dielectric properties, there are problems of low glass transition temperature, high melt viscosity, and poor processability.

[0011] In view of the above aspects, an object of embodiments of the present application is to provide a thermosetting resin that can balance dielectric properties and glass transition temperature, and has low melt viscosity.

[0012] Techniques for solving problems

[0013] The present application includes the embodiments shown below.

[0014] [1] A thermosetting resin which is a linear copolymer and has a repeating unit corresponding to a monovinyl aromatic compound, a repeating unit corresponding to a divinyl aromatic compound, and a repeating unit corresponding to an aromatic ring-condensed cyclic olefin compound.

[0015] [2] The thermosetting resin according to [1], wherein the content of the repeating unit corresponding to the aromatic ring-condensed cyclic olefin compound is 5 to 80 mol% in 100 mol% of the total repeating units.

[0016] [3] The thermosetting resin according to [1] or [2], wherein the linear copolymer has a structure of a polymerization initiator represented by general formula (1) at the terminal: R 1 -N=N-R 2 at the terminal of the linear copolymer. 1 and R 2 each independently represent a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group.

[0017] [4] The thermosetting resin according to any one of [1] to [3], wherein the total content of the repeating unit corresponding to the monovinyl aromatic compound, the repeating unit corresponding to the divinyl aromatic compound, and the repeating unit corresponding to the aromatic ring-condensed cyclic olefin compound is 80 mol% or more in 100 mol% of the total repeating units.

[0018] [5] The thermosetting resin according to any one of [1] to [4], wherein the number of rings of the aromatic ring-condensed cyclic olefin compound is 3 or less.

[0019] [6] A cured product obtained by curing the thermosetting resin according to any one of [1] to [5].

[0020] [7] A thermosetting composition comprising the thermosetting resin according to any one of [1] to [5].

[0021] [8] The thermosetting composition according to [7], which is a printed board material.

[0022] Effects of the Invention

[0023] According to the embodiments of the present application, a thermosetting resin which can balance dielectric properties and glass transition temperature and has low melt viscosity can be obtained. DETAILED DESCRIPTION

[0024] The thermosetting resin of the present embodiment is a copolymer having (A) a repeating unit corresponding to a monovinyl aromatic compound, (B) a repeating unit corresponding to a divinyl aromatic compound, and (C) a repeating unit corresponding to an aromatic ring-condensed cyclic olefin compound.

[0025] The repeating unit corresponding to the monovinyl aromatic compound (hereinafter, also referred to as "monovinyl aromatic compound unit") is a structural unit of the copolymer, and is a structural unit having a structure formed by addition polymerization of a monovinyl aromatic compound as a monomer. The repeating unit, if having a structure corresponding to the monovinyl aromatic compound, is not necessarily limited to one formed by polymerization using the monovinyl aromatic compound, but can be one formed by further reacting after polymerization to form a structure corresponding to the monovinyl aromatic compound.

[0026] As the monovinyl aromatic compound unit, a repeating unit having a structure in which a vinyl group of a monovinyl aromatic compound becomes a single bond by addition polymerization, as represented by the following general formula (2), can be exemplified.

[0027] [Chemical Formula 1]

[0028]

[0029] In formula (2), R 3 represents a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. More specifically, R 3 A monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms (more preferably 6 to 20 carbon atoms) selected from the group consisting of a phenyl group which can have a substituent, a biphenyl group which can have a substituent, a naphthyl group which can have a substituent, and a terphenyl group which can have a substituent can be exemplified. Here, the number of carbon atoms of R 3 , in the case of having an alkyl group or the like as a substituent, is the number of carbon atoms of R 3 as a whole.

[0030] As the monovinyl aromatic compound forming such a repeating unit, an aromatic compound having one vinyl group is sufficient, and for example, a vinyl aromatic compound such as styrene, vinyl naphthalene, vinyl biphenyl, an alkylstyrene (for example, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene), a dialkylstyrene (for example, 3,5-dimethylstyrene, 2,5-dimethylstyrene, 2,5-diethylstyrene), an alkylvinylbiphenyl (for example, ethylvinylbiphenyl), an alkylvinyl naphthalene (for example, ethylvinyl naphthalene), or the like can be exemplified, and any one of these or two or more of these can be used in combination.

[0031] In one embodiment, the monovinyl aromatic compound preferably contains at least one selected from the group consisting of styrene, vinyl naphthalene, vinyl biphenyl, alkyl styrene, dialkyl styrene, alkyl vinyl biphenyl, and alkyl vinyl naphthalene (A1). In this case, the amount of the repeating unit corresponding to the at least one (A1) in 100 mol% of the monovinyl aromatic compound unit is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more, and can be 100 mol%.

[0032] In one embodiment, the monovinyl aromatic compound preferably contains styrene. In this case, the amount of the repeating unit corresponding to styrene (hereinafter, also referred to as "styrene unit") in 100 mol% of the monovinyl aromatic compound unit is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more, and can be 100 mol%.

[0033] The repeating unit corresponding to the divinyl aromatic compound (hereinafter, also referred to as "divinyl aromatic compound unit") described above (B) is a structural unit of the copolymer described above, and has a structure of having one vinyl group by addition polymerization of the divinyl aromatic compound as a monomer. This repeating unit, if it is a structure corresponding to the divinyl aromatic compound, is not necessarily limited to one formed by polymerization using the divinyl aromatic compound, and can be one formed by further reacting after polymerization to form a structure corresponding to the divinyl aromatic compound.

[0034] As the divinyl aromatic compound unit, a repeating unit having a structure in which one vinyl group of the divinyl aromatic compound is a single bond by addition polymerization as represented by the following general formula (3) can be exemplified.

[0035] [Chem. 2]

[0036]

[0037] In formula (3), R 4 represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. More specifically, R 4 A divalent aromatic hydrocarbon group having 6 to 30 carbon atoms (more preferably 6 to 20 carbon atoms) selected from the group consisting of a phenylene group which can have a substituent, a biphenylene group which can have a substituent, a naphthylene group which can have a substituent, and a terphenylene group which can have a substituent can be exemplified. Here, the carbon atom number of R 4 in the case where the substituent such as an alkyl group is present, is the number of carbon atoms of R 4 as a whole including the carbon atoms included in the substituent.

[0038] As the divinyl aromatic compound forming such a repeating unit, any aromatic compound having two vinyl groups can be used, and examples include divinylbenzene (including positional isomers or a mixture thereof), divinyl naphthalene (including positional isomers or a mixture thereof), and divinyl biphenyl (including positional isomers or a mixture thereof). Any one of these or two or more of these can be used in combination.

[0039] In one embodiment, the divinyl aromatic compound preferably contains at least one (B1) selected from the group consisting of divinylbenzene, divinyl naphthalene, and divinyl biphenyl. In this case, the amount of the repeating unit corresponding to the at least one (B1) in 100 mol% of the divinyl aromatic compound unit is preferably 70 mol% or greater, more preferably 80 mol% or greater, and further preferably 90 mol% or greater, and can be 100 mol%.

[0040] In one embodiment, the divinyl aromatic compound preferably contains divinylbenzene (meta, para, or a positional isomer mixture thereof). In this case, the amount of the repeating unit corresponding to divinylbenzene (hereinafter also referred to as "divinylbenzene unit") in 100 mol% of the divinyl aromatic compound unit is preferably 70 mol% or greater, more preferably 80 mol% or greater, and further preferably 90 mol% or greater, and can be 100 mol%.

[0041] The repeating unit corresponding to the aromatic ring-condensed cyclic olefin compound (hereinafter also referred to as "cyclic olefin unit") described above (C) is a structural unit of the copolymer described above, and is a structural unit having a structure formed by addition polymerization of the aromatic ring-condensed cyclic olefin compound as a monomer. This repeating unit, if having a structure corresponding to the aromatic ring-condensed cyclic olefin compound, is not necessarily limited to a unit formed by polymerization using the aromatic ring-condensed cyclic olefin compound, and can be a unit formed by further reacting after polymerization to form a structure corresponding to the aromatic ring-condensed cyclic olefin compound.

[0042] The aromatic ring-condensed cyclic olefin compound is a cyclic olefin compound condensed with an aromatic ring, and more specifically, is a compound having a condensed ring of an aliphatic ring having a carbon-carbon double bond and an aromatic ring. The condensation can be ortho condensation or ortho-para condensation. As the aromatic ring-condensed cyclic olefin compound, for example, there can be mentioned indene-based compounds, acenaphthylene-based compounds, phenalene-based compounds, acephenanthrene-based compounds, aceanthrene-based compounds, benzofuran-based compounds, benzothiophene-based compounds, and the like, which can be used singly or in combination of two or more. Among these, as the aromatic ring-condensed cyclic olefin compound, a compound having three or less rings is preferred. Specifically, as the compound having two rings, indene-based compounds, benzofuran-based compounds, benzothiophene-based compounds are preferred; and as the compound having three rings, acenaphthylene-based compounds, phenalene-based compounds, and more preferably, indene-based compounds and / or acenaphthylene-based compounds are preferred.

[0043] In one embodiment, the aromatic ring-condensed cyclic olefin compound preferably contains at least one (C1) selected from the group consisting of indene-based compounds, acenaphthylene-based compounds, phenalene-based compounds, acephenanthrene-based compounds, aceanthrene-based compounds, benzofuran-based compounds, and benzothiophene-based compounds. In this case, the amount of the repeating unit corresponding to the at least one (C1) in 100 mol% of the cyclic olefin unit is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more, and can be 100 mol%.

[0044] As the indene-based compound, for example, there can be mentioned at least one selected from the group consisting of indene, alkylindene, halogenated indene, arylindene, and alkoxyindene.

[0045] As the acenaphthylene-based compound, for example, there can be mentioned at least one selected from the group consisting of acenaphthylene, alkylacenaphthylene, halogenated acenaphthylene, arylacenaphthylene, and alkoxyacenaphthylene.

[0046] As the phenalene-based compound, for example, there can be mentioned at least one selected from the group consisting of phenalene, alkylphenalene, halogenated phenalene, arylphenalene, and alkoxyphenalene.

[0047] In one embodiment, as the cyclic olefin unit, there can be mentioned a repeating unit represented by the following general formula (4).

[0048] [Chem. 3]

[0049]

[0050] In formula (4), R 5 and R 6each independently represents an alkyl group having 1 to 20 carbon atoms, a halogen atom, an aryl group having 6 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. m and n each independently represent an integer of 0 to 3. In the case where m and n are 2 or more, R 5 and R 6 may be the same or different.

[0051] The aromatic ring condensation cyclic olefin compound forming the repeating unit of formula (4) is a acenaphthylene compound represented by the following general formula (5).

[0052] [Chem. 4]

[0053]

[0054] R 5 , R 6 , m and n in formula (5) are the same as R 5 , R 6 , m and n in formula (4).

[0055] In one embodiment, the aromatic ring condensation cyclic olefin compound preferably contains the acenaphthylene compound represented by the above formula (5), and more preferably contains acenaphthylene. In this case, the amount of the repeating unit represented by formula (4) (preferably the repeating unit corresponding to acenaphthylene (hereinafter, also referred to as "acenaphthylene unit")) in 100 mol% of the cyclic olefin unit is preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, and can be 100 mol%.

[0056] The thermosetting resin of the present embodiment is a linear copolymer having the above three repeating units. The formability is improved by the entanglement of the molecular chains due to the linear structure. Here, the linear structure means that the repeating units constituting the copolymer are connected to each other in one-dimensional chain and bonded to form a structure, and means a structure that does not have a crosslinked structure.

[0057] In the thermosetting resin, the arrangement order of the monovinyl aromatic compound unit, the divinyl aromatic compound unit, and the cyclic olefin unit can be regularly arranged, or can be randomly arranged. The thermosetting resin is preferably a random copolymer in which the monovinyl aromatic compound unit, the divinyl aromatic compound unit, and the cyclic olefin unit are randomly arranged.

[0058] The thermosetting resin can contain, in addition to the monovinyl aromatic compound unit, the divinyl aromatic compound unit, and the cyclic olefin unit, a repeating unit corresponding to other monomers, within a range that does not impair the effects thereof. As such other monomers, for example, a trivinyl aromatic compound, a trivinyl aliphatic compound, a divinyl aliphatic compound, a monovinyl aliphatic compound, or the like can be exemplified.

[0059] In the thermosetting resin, the content of the monovinyl aromatic compound unit is not particularly limited, and the content of the monovinyl aromatic compound unit is preferably 15 mol% to 90 mol% in 100 mol% of the total repeating units constituting the copolymer. By being 15 mol% or more, the effect of reducing the melt viscosity is excellent. The content of the monovinyl aromatic compound unit is more preferably 30 mol% to 80 mol%, further preferably 40 mol% to 75 mol%, and further preferably 50 mol% to 70 mol%. In the present specification, the structure derived from the polymerization initiator present at the terminal of the copolymer is not included in 100 mol% of the total repeating units.

[0060] In the thermosetting resin, the content of the divinyl aromatic compound unit is not particularly limited, and the content of the divinyl aromatic compound unit is preferably 3 mol% to 30 mol% in 100 mol% of the total repeating units constituting the copolymer. By being 3 mol% or more, the thermosetting can be improved to obtain a good cured product, and the glass transition temperature can be improved. The content of the divinyl aromatic compound unit is more preferably 5 mol% to 25 mol%, further preferably 8 mol% to 22 mol%, and further preferably 10 mol% to 20 mol%.

[0061] In the thermosetting resin, the content of the cyclic olefin unit is not particularly limited, and the content of the cyclic olefin unit is preferably 5 mol% to 80 mol% in 100 mol% of the total repeating units constituting the copolymer. By being 5 mol% or more, the effect of improving the glass transition temperature is excellent. By being 80 mol% or less, the effect of reducing the melt viscosity is excellent. The content of the cyclic olefin unit is more preferably 7 mol% to 50 mol%, further preferably 8 mol% to 35 mol%, and further preferably 10 mol% to 30 mol%.

[0062] In 100 mol% of the total repeating units constituting the copolymer, the total content of the monovinyl aromatic compound unit, the divinyl aromatic compound unit, and the cyclic olefin unit is preferably 80 mol% or more, more preferably 90 mol% or more, and can be 100 mol%.

[0063] In one embodiment, the thermosetting resin is preferably a copolymer having the repeating unit represented by the above formula (2) (preferably a styrene unit), the repeating unit represented by the above formula (3) (preferably a divinylbenzene unit), and the repeating unit represented by the above formula (4) (preferably an acenaphthylene unit). In this case, when the total repeating units constituting the copolymer are taken as 100 mol%, the thermosetting resin preferably contains each repeating unit as follows. Further, in this case, these repeating units and the repeating units of the above (A), (B), or (C) other than the repeating units can be contained.

[0064] • the repeating unit represented by formula (2) (preferably a styrene unit): 15 to 90 mol%, preferably 30 to 80 mol%, more preferably 40 to 75 mol%, further preferably 50 to 70 mol%.

[0065] • the repeating unit represented by formula (3) (preferably a divinylbenzene unit): 3 to 30 mol%, preferably 5 to 25 mol%, more preferably 8 to 22 mol%, further preferably 10 to 20 mol%.

[0066] • the repeating unit represented by formula (4) (preferably an acenaphthylene unit): 5 to 80 mol%, preferably 7 to 50 mol%, more preferably 8 to 35 mol%, further preferably 10 to 30 mol%.

[0067] The thermosetting resin can have at least one of a structure derived from a polymerization initiator represented by the following general formula (1) or a structure derived from a polymerization initiator represented by the following general formula (6) at the terminal of the linear copolymer. The polymerization initiator represented by formula (1) is an azo initiator having no cyano group, unlike azobisisobutyronitrile (AIBN) which is a general-purpose azo initiator. The polymerization initiator represented by formula (6) is an organic peroxide such as a dialkyl peroxide. Among them, by using the polymerization initiator represented by formula (1), more excellent dielectric properties can be imparted.

[0068] R 1 -N=N-R 2 (1)R 7 -O-O-R 8 (6)

[0069] In formula (1) and formula (6), R 1 , R 2 , R 7 , and R 8each independently represents a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group, and does not contain a hetero atom. The number of carbon atoms of the saturated hydrocarbon group is not particularly limited, and is preferably from 1 to 23, more preferably from 4 to 13. The number of carbon atoms of the aromatic hydrocarbon group is not particularly limited, and is preferably from 6 to 23, more preferably from 6 to 13.

[0070] As the saturated hydrocarbon group, a branched or straight-chain saturated aliphatic hydrocarbon group (alkyl group) can be used, or a saturated alicyclic hydrocarbon group can be used. As a specific example of the saturated hydrocarbon group, an alkyl group such as a t-butyl group, a t-amyl group, a t-hexyl group, a 1,1,3,3-tetramethylbutyl group, and the like, a saturated alicyclic hydrocarbon group such as a cyclohexyl group can be exemplified.

[0071] As a specific example of the aromatic hydrocarbon group, an aryl group such as a phenyl group, a tolyl group, a naphthyl group, and the like, an aralkyl group such as a cumyl group, a benzyl group, a phenethyl group, and the like can be exemplified.

[0072] In one embodiment, R 1 , R 2 , R 7 , and R 8 may each independently be a group represented by the following general formula (7).

[0073] [Chemical Formula 5]

[0074]

[0075] In formula (7), R 9 , R 10 , and R 11 each independently represent a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group. More preferably, R 9 represents a monovalent saturated hydrocarbon group having from 1 to 20 carbon atoms (more preferably from 1 to 10 carbon atoms) or a monovalent aromatic hydrocarbon group having from 6 to 20 carbon atoms (more preferably from 6 to 10 carbon atoms), R 10 and R 11 each represent a methyl group. As the saturated hydrocarbon group with respect to R 9 , R 10 , and R 11 (preferably R 9 ), a branched chain or a straight chain can be used, and an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, an isopropyl group, a t-butyl group, a 2,2-dimethylpropyl group, and the like, a saturated alicyclic hydrocarbon group such as a cyclohexyl group can be exemplified. As the aromatic hydrocarbon group with respect to R 9 , R 10 , and R 11 (preferably R 9 ), an aryl group such as a phenyl group, a tolyl group, a naphthyl group, and the like can be exemplified.

[0076] In the case of synthesizing a vinyl copolymer by radical polymerization using these polymerization initiators, generally both terminals of the obtained vinyl copolymer become the structure derived from the polymerization initiator. In the case of polymerization using the polymerization initiator of the above formula (1), a copolymer having R 1 - and / or R 2 - at both terminals can be obtained. That is, both terminals of the copolymer can be R 1 -, can be R 2 -, or one terminal can be R 1 - and the other terminal can be R 2 -. On the other hand, in the case of polymerization using the polymerization initiator of the above formula (6), a copolymer having R 7 O- and / or R 8 O- at both terminals can be obtained. That is, both terminals of the copolymer can be R 7 O-, can be R 8 O-, or one terminal can be R 7 O- and the other terminal can be R 8 O-.

[0077] The weight average molecular weight Mw of the thermosetting resin is not particularly limited, and for example, can be 1 thousand to 100 thousand, can be 2 thousand to 5 thousand, or can be 3 thousand to 2 thousand. By making the weight average molecular weight Mw 1 thousand or more, it is possible to reduce the concentration of the terminal group derived from the polymerization initiator and improve the dielectric properties. In addition, by making the weight average molecular weight Mw 100 thousand or less, it is possible to reduce the melt viscosity. Here, the weight average molecular weight Mw is the polystyrene conversion weight average molecular weight measured by gel permeation chromatography (GPC).

[0078] The production method of the thermosetting resin is not particularly limited. As a method for synthesizing a linear copolymer, in the production method of the preferred embodiment, at least one of the polymerization initiators represented by the above formula (1) or the polymerization initiator represented by formula (6) is used, a vinylbenzyl phosphonium salt, a monovinyl aromatic compound, and an aromatic ring condensed cyclic olefin compound are copolymerized, and the obtained copolymer is reacted with formaldehyde. However, it is not limited to this production method.

[0079] As the vinylbenzyl phosphonium salt, it is preferable to use a vinylbenzyl phosphonium halide. As the phosphonium group in the vinylbenzyl phosphonium salt, for example, quaternary phosphonium groups such as trialkylphosphonium, triarylphosphonium, and triarylalkylphosphonium can be exemplified. In addition, as the halogen that forms a salt with the phosphonium group, for example, chlorine, bromine, and the like can be exemplified.

[0080] As the method for copolymerizing the vinylbenzylphosphonium salt with the monovinyl aromatic compound and the aromatic ring condensed cyclic olefin compound, a publicly known vinyl polymerization method can be used. By using the radical polymerization initiator represented by the above formula (1) and / or formula (6) as a polymerization initiator, a copolymer having a repeating unit derived from the vinylbenzylphosphonium salt, a repeating unit derived from the monovinyl aromatic compound, and a repeating unit derived from the aromatic ring condensed cyclic olefin compound can be obtained. At the time of polymerization, a chain transfer agent can be added, and the molecular weight of the copolymer can be adjusted.

[0081] Further, as the method for reacting the obtained copolymer with formaldehyde, a publicly known Wittig reaction can be used, and the copolymer is reacted with formaldehyde by being treated with a base, whereby a phosphonium group is removed and a vinyl group is introduced.

[0082] If this production method, in the copolymerization step, the vinylbenzylphosphonium salt is a monovinyl group, and thus a linear copolymer having no branch is obtained, and after the copolymerization, a vinyl group is introduced into the repeating unit derived from the vinylbenzylphosphonium salt, and thus a linear copolymer having a repeating unit corresponding to a divinyl aromatic compound and having no branch can be obtained.

[0083] The thermosetting composition of the present embodiment contains the above-described thermosetting resin. As for the content of the thermosetting resin in the thermosetting composition, there is no particular limitation as long as the composition has a property of being cured by heat. For example, it can be 1 to 99 mass% or 10 to 95 mass% with respect to 100 mass% of the solid content of the thermosetting composition (the amount excluding the organic solvent in the case of containing the organic solvent described later, or the entire amount of the composition in the case of not containing the organic solvent).

[0084] In the thermosetting composition, in addition to containing the above-described thermosetting resin, for example, other thermosetting resins (thermosetting crosslinking agents), thermoplastic resins, fillers, flame retardants, curing accelerators, polymerization initiators, defoaming agents, heat stabilizers, antistatic agents, ultraviolet absorbers, colorants such as dyes or pigments, lubricants, dispersants, and the like can be contained.

[0085] In addition, the thermosetting composition can contain an organic solvent to adjust the viscosity thereof, and the thermosetting composition can be a solution containing the above-described thermosetting resin. As the organic solvent, one that can dissolve the above-described thermosetting resin can be used, and for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like can be exemplified as ketones, ethyl acetate, propyl acetate, butyl acetate, and the like can be exemplified as esters; dimethylacetamide, dimethylformamide, and the like can be exemplified as amides; toluene, xylene, and the like can be exemplified as aromatic hydrocarbons, and the like can be used. One of these or two or more of these can be used in combination.

[0086] The thermosetting resin or thermosetting composition of the present embodiment can be crosslinked by polymerization due to the vinyl group in the molecular chain of the copolymer, and a cured product can be obtained by thermal curing. Since the cured product has low dielectric loss tangent and dielectric constant, and excellent dielectric properties, it can be used, for example, for electronic material applications such as printed board materials, semiconductor sealing materials, and the like. That is, the thermosetting composition of an embodiment is an electronic material thermosetting composition.

[0087] As the printed board material, there can be mentioned rigid printed board materials such as single-sided boards, double-sided boards, multilayer boards, build-up boards, and the like, or flexible printed board materials in the form of films or sheets, and the like. In addition, since the dielectric properties are excellent, it can be preferably used as a high-frequency board material used in high-frequency communication equipment.

[0088] Examples

[0089] Hereinafter, the present application will be described more specifically using examples, but the present application is not limited to the following examples.

[0090] <Measurement and Evaluation Methods>

[0091] [Molar ratio of styrene / divinylbenzene / acetylene]

[0092] Regarding the products and compositions obtained in Examples 1 to 9, Examples 11 to 13, Comparative Example 1, Comparative Examples 4 to 6, and Comparative Example 9, NMR measurement was performed using a nuclear magnetic resonance device (manufactured by JEOL) after dissolving in deuterated chloroform. 1 H-NMR measurement was performed to obtain the molar ratio of the repeating units corresponding to styrene, the repeating units corresponding to divinylbenzene, and the repeating units corresponding to acetylene, and the content of the repeating units corresponding to styrene (styrene ratio), the content of the repeating units corresponding to divinylbenzene (divinylbenzene ratio), and the content of the repeating units corresponding to acetylene (acetylene ratio) were calculated with respect to 100 mol% of the total repeating units.

[0093] [Molar ratio of styrene / divinylbenzene / acetylene / vinylcyclohexane]

[0094] Regarding the products obtained in Example 10, Comparative Example 2, and Comparative Example 7, NMR measurement was performed using a nuclear magnetic resonance device (manufactured by JEOL) after dissolving in deuterated chloroform. 1The molar ratio of the repeating unit corresponding to styrene, the repeating unit corresponding to divinylbenzene, the repeating unit corresponding to acetylene, and the repeating unit corresponding to vinylcyclohexane was determined by H-NMR measurement, and the content of the repeating unit corresponding to styrene (styrene ratio), the content of the repeating unit corresponding to divinylbenzene (divinylbenzene ratio), the content of the repeating unit corresponding to acetylene (acetylene ratio), and the content of the repeating unit corresponding to vinylcyclohexane (vinylcyclohexane ratio) were calculated with respect to 100 mol% of the total repeating units.

[0095] [molar ratio of styrene / divinylbenzene / isobornyl acrylate]

[0096] The products obtained in Comparative Example 3 and Comparative Example 8 were dissolved in deuterated chloroform, and the number average molecular weight was measured by gel permeation chromatography (GPC) (Prominence, Shimadzu Corporation) using a four-tube column (Shodex GPC columns KF-601, KF-602, KF-603, KF-604, manufactured by Showa Denko) connected with a polystyrene-based gel as a filler. 1 The molar ratio of the repeating unit corresponding to styrene, the repeating unit corresponding to divinylbenzene, and the repeating unit corresponding to isobornyl acrylate was determined by H-NMR measurement, and the content of the repeating unit corresponding to styrene (styrene ratio), the content of the repeating unit corresponding to divinylbenzene (divinylbenzene ratio), and the content of the repeating unit corresponding to isobornyl acrylate (isobornyl acrylate ratio) were calculated with respect to 100 mol% of the total repeating units.

[0097] [weight average molecular weight]

[0098] The products and compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 9 were dissolved in tetrahydrofuran, and the weight average molecular weight Mw in polystyrene conversion was measured by gel permeation chromatography (GPC) (Prominence, Shimadzu Corporation) using a four-tube column (Shodex GPC columns KF-601, KF-602, KF-603, KF-604, manufactured by Showa Denko) connected with a polystyrene-based gel as a filler. The column oven temperature was set to 40°C, the THF flow rate was 0.6 mL / min, the sample concentration was 0.1 mass%, the sample injection amount was 10 μL, and a differential refractive index detector (Shodex RI-504, manufactured by Showa Denko) was used.

[0099] [dielectric constant, dielectric loss tangent]

[0100] The products and compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 9 were used as test samples. Using a single-acting compression molding machine (manufactured by Yasuda Seiki Co., Ltd.), 1.5 g of the test sample was pressed for 15 minutes at a pressure of 10 MPa and a temperature of 220°C to produce a 30 mm × 30 mm × 1 mm thick plate. The obtained plate was cut to produce test pieces with a width of 2 mm, a thickness of 1 mm, and a length of 30 mm. For these test pieces, the dielectric constant and dielectric loss tangent at 10 GHz were measured using a cavity resonator method dielectric constant measuring device (manufactured by KEYSIGHT), and evaluated according to the following criteria.

[0101] Dielectric constants less than 2.4 are designated as "A" (Excellent), those above 2.4 but less than 2.5 are designated as "B" (Good), those above 2.5 but less than 2.6 are designated as "C" (Average), those above 2.6 but less than 2.7 are designated as "D" (Poor), and those above 2.7 are designated as "E" (Inferior).

[0102] Dielectric loss tangent less than 0.001 is designated as "A" (Excellent), 0.001 or more but less than 0.002 is designated as "B" (Good), 0.002 or more but less than 0.003 is designated as "C" (Average), 0.003 or more but less than 0.004 is designated as "D" (Poor), and 0.004 or more is designated as "E" (Inferior).

[0103] [Glass transition temperature Tg]

[0104] The plates prepared in the above [dielectric constant, dielectric loss tangent] were cut to produce test pieces with a width of 5 mm, a thickness of 1 mm, and a length of 25 mm. The glass transition temperature of these test pieces was measured using a dynamic viscoelasticity measuring device: Rheogel-E4000 (manufactured by Eubeem Co., Ltd.). For each test piece, the maximum value of the loss tangent (tanδ) measured under the conditions of a tensile sinusoidal wave, a dynamic strain of 5 μm, a frequency of 1 Hz, and a heating rate of 3 °C / min was taken as the glass transition temperature. Those with a glass transition temperature of 180 °C or higher were designated as "A" (Excellent), those above 170 °C but below 180 °C as "B" (Good), those above 160 °C but below 170 °C as "C" (Average), and those below 160 °C as "D" (Poor).

[0105] [Melt viscosity (minimum melt viscosity)]

[0106] The products and compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 9 were used as samples. Using a manual hydraulic pump: P-1B (Riken Kako), 0.4 g of the sample was pressed at a pressure of 10 MPa for 1 minute to produce a pellet having a diameter of 20 mm x thickness of 1 mm. The obtained pellet was used as a sample, and using a rheometer: MCR 302 (manufactured by Anton Paar), the sample was warmed from 50°C to 200°C at a temperature increase rate of 5°C / minute. The minimum value of the complex viscosity was taken as the minimum melt viscosity, and those having a minimum melt viscosity of less than 100,000 poise were taken as "O" (low viscosity), and those having a minimum melt viscosity of 100,000 poise or more were taken as "X" (high viscosity).

[0107] (Synthetic Example 1) Synthesis of Compound 1: Vinylbenzyltriphenylphosphonium Chloride

[0108] Vinylbenzyl chloride (trade name: CMS-14, manufactured by AGC Seimi Chemical Co., Ltd.), 1.5 moles (228.9 g), triphenylphosphine, 1.8 moles (472.1 g), and dimethylformamide, 622.4 g were charged into a 2.0-L reactor, and reacted at 70°C for 3 hours under a nitrogen atmosphere, whereby white solid was precipitated. After the solid was sufficiently washed with acetone, drying was performed under reduced pressure at 92°C, whereby 490 g of Compound 1 was recovered.

[0109] (Synthetic Example 2) Synthesis of Copolymer A

[0110] Styrene, 15.1 g, Compound 1, 13.2 g, acenaphthylene, 5.5 g, 2,4-diphenyl-4-methyl-1-pentene as a chain transfer agent, 3.5 g, 2,2'-azobis(2,4,4-trimethylpentane) (trade name: VR-110, manufactured by FUJIFILM Wako Pure Chemical Corporation), 1.28 g, and dimethylformamide, 78.8 g were charged into a 500-mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, whereby Copolymer A was obtained as a dimethylformamide solution.

[0111] (Synthetic Example 3) Synthesis of Copolymer B

[0112] Styrene, 12.7 g, Compound 1, 16.0 g, acenaphthylene, 5.0 g, 2,4-diphenyl-4-methyl-1-pentene, 3.5 g, 2,2'-azobis(2,4,4-trimethylpentane), 1.28 g, and dimethylformamide, 78.7 g were charged into a 500-mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, whereby Copolymer B was obtained as a dimethylformamide solution.

[0113] (Synthetic Example 4) Synthesis of Copolymer C

[0114] Styrene 18.5 g, 10.1 g of compound 1, acenaphthylene 6.3 g, 2,4-diphenyl-4-methyl-1-pentene 3.6 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.33 g, and dimethylformamide 81.5 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, thereby obtaining copolymer C as a dimethylformamide solution.

[0115] (Synthetic Example 5) Synthesis of Copolymer D

[0116] Styrene 17.3 g, 13.5 g of compound 1, acenaphthylene 2.8 g, 2,4-diphenyl-4-methyl-1-pentene 3.5 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.27 g, and dimethylformamide 78.2 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, thereby obtaining copolymer D as a dimethylformamide solution.

[0117] (Synthetic Example 6) Synthesis of Copolymer E

[0118] Styrene 12.8 g, 12.8 g of compound 1, acenaphthylene 8.0 g, 2,4-diphenyl-4-methyl-1-pentene 3.5 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.28 g, and dimethylformamide 78.4 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, thereby obtaining copolymer E as a dimethylformamide solution.

[0119] (Synthetic Example 7) Synthesis of Copolymer F

[0120] Styrene 17.7 g, 10.3 g of compound 1, acenaphthylene 8.0 g, 2,4-diphenyl-4-methyl-1-pentene 3.7 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.37 g, and dimethylformamide 83.9 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, thereby obtaining copolymer F as a dimethylformamide solution.

[0121] (Synthetic Example 8) Synthesis of Copolymer G

[0122] Styrene 13.4 g, 15.8 g of compound 1, acenaphthylene 3.7 g, 2,4-diphenyl-4-methyl-1-pentene 3.4 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.25 g, and dimethylformamide 76.7 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, thereby obtaining copolymer G as a dimethylformamide solution.

[0123] (Synthetic Example 9) Synthesis of Copolymer H

[0124] Styrene 10.2 g, 15.0 g of Compound 1, acenaphthylene 7.0 g, 2,4-diphenyl-4-methyl-l-pentene 3.4 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.22 g, and dimethylformamide 75.2 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, whereby a copolymer H was obtained as a dimethylformamide solution.

[0125] (Synthetic Example 10) Synthesis of Copolymer I

[0126] Styrene 21.7 g, 10.6 g of Compound 1, acenaphthylene 3.3 g, 2,4-diphenyl-4-methyl-l-pentene 3.7 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.35 g, and dimethylformamide 82.9 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, whereby a copolymer I was obtained as a dimethylformamide solution.

[0127] (Synthetic Example 11) Synthesis of Copolymer J

[0128] Styrene 9.7 g, 12.0 g of Compound 1, acenaphthylene 5.0 g, vinylcyclohexane 8.5 g, 2,4-diphenyl-4-methyl-l-pentene 3.8 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.34 g, and dimethylformamide 82.2 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, whereby a copolymer J was obtained as a dimethylformamide solution.

[0129] (Synthetic Example 12) Synthesis of Copolymer K

[0130] Styrene 18.5 g, 10.1 g of Compound 1, acenaphthylene 6.3 g, 2,4-diphenyl-4-methyl-l-pentene 3.7 g, di-t-butyl peroxide (trade name: Perbutyl D, manufactured by Nippon Oil) as a polymerization initiator 0.77 g, and dimethylformamide 81.5 g were put into a 500 mL reactor, and reacted at 132°C for 3 hours under a nitrogen atmosphere, whereby a copolymer K was obtained as a dimethylformamide solution.

[0131] (Synthetic Example 13) Synthesis of Copolymer L

[0132] Styrene 15.1 g, 13.2 g of compound 1, acenaphthylene 5.5 g, 2,4-diphenyl-4-methyl-1-pentene 1.8 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.28 g, and dimethylformamide 78.8 g were put into a 500 mL reactor, and reacted at 120°C for 3.5 hours under a nitrogen atmosphere to obtain copolymer L as a dimethylformamide solution.

[0133] (Synthetic Example 14) Synthesis of Copolymer M

[0134] Styrene 18.5 g, 10.1 g of compound 1, acenaphthylene 6.3 g, 2,4-diphenyl-4-methyl-1-pentene 7.3 g, 2,2'-azobis(2,4,4-trimethylpentane) 2.65 g, and dimethylformamide 81.5 g were put into a 500 mL reactor, and reacted at 120°C for 1.5 hours under a nitrogen atmosphere to obtain copolymer M as a dimethylformamide solution.

[0135] (Comparative Synthetic Example 1) Synthesis of Copolymer N

[0136] Styrene 22.0 g, 15.5 g of compound 1, 2,4-diphenyl-4-methyl-1-pentene 3.9 g, di-t-butyl peroxide 0.82 g, and dimethylformamide 87.4 g were put into a 500 mL reactor, and reacted at 132°C for 3 hours under a nitrogen atmosphere to obtain copolymer N as a dimethylformamide solution.

[0137] (Comparative Synthetic Example 2) Synthesis of Copolymer O

[0138] Styrene 14.3 g, 12.4 g of compound 1, vinylcyclohexane 8.0 g, 2,4-diphenyl-4-methyl-1-pentene 3.7 g, di-t-butyl peroxide 0.76 g, and dimethylformamide 81.0 g were put into a 500 mL reactor, and reacted at 132°C for 3 hours under a nitrogen atmosphere to obtain copolymer O as a dimethylformamide solution.

[0139] (Comparative Synthetic Example 3) Synthesis of Copolymer P

[0140] Styrene 14.1 g, 11.4 g of compound 1, isobornyl acrylate 8.0 g, 2,4-diphenyl-4-methyl-1-pentene 3.5 g, di-t-butyl peroxide 0.74 g, and dimethylformamide 78.3 g were put into a 500 mL reactor, and reacted at 132°C for 3 hours under a nitrogen atmosphere to obtain copolymer P as a dimethylformamide solution.

[0141] (Comparative Synthetic Example 4) Synthesis of Copolymer Q

[0142] Styrene 22.0 g, 15.5 g of Compound 1, 2, 4-diphenyl-4-methyl-l-pentene 3.9 g, 2, 2'-azobis (2, 4, 4-trimethylpentane) 1.42 g, and dimethylformamide 87.4 g were charged into a 500 mL reactor, and reacted at 120°C for 2 hours under a nitrogen atmosphere, to thereby obtain a copolymer Q as a dimethylformamide solution.

[0143] (Synthetic Example 5) Synthesis of Copolymer R

[0144] Styrene 22.0 g, 15.5 g of Compound 1, 2, 4-diphenyl-4-methyl-l-pentene 3.9 g, 2, 2'-azobis (2, 4, 4-trimethylpentane) 1.42 g, and dimethylformamide 87.4 g were charged into a 500 mL reactor, and reacted at 120°C for 2 hours under a nitrogen atmosphere, to thereby obtain a copolymer Q as a dimethylformamide solution.

[0145] (Synthetic Example 6) Synthesis of Copolymer S

[0146] Styrene 22.0 g, 15.5 g of Compound 1, 2, 4-diphenyl-4-methyl-l-pentene 3.9 g, 2, 2'-azobis (2, 4, 4-trimethylpentane) 1.42 g, and dimethylformamide 87.4 g were charged into a 500 mL reactor, and reacted at 120°C for 2 hours under a nitrogen atmosphere, to thereby obtain a copolymer Q as a dimethylformamide solution.

[0147] (Synthetic Example 7) Synthesis of Copolymer T

[0148] Styrene 22.0 g, 15.5 g of Compound 1, 2, 4-diphenyl-4-methyl-l-pentene 3.9 g, 2, 2'-azobis (2, 4, 4-trimethylpentane) 1.42 g, and dimethylformamide 87.4 g were charged into a 500 mL reactor, and reacted at 120°C for 2 hours under a nitrogen atmosphere, to thereby obtain a copolymer Q as a dimethylformamide solution.

[0149] (Synthetic Example 8) Synthesis of Copolymer U

[0150] Acenaphthylene 35.0 g, 2, 4-diphenyl-4-methyl-l-pentene 3.6 g, 2, 2'-azobis (2, 4, 4-trimethylpentane) 1.33 g, and dimethylformamide 81.7 g were charged into a 500 mL reactor, and reacted at 120°C for 4 hours under a nitrogen atmosphere. The reaction solution was reprecipitated in a large excess of methanol, and the supernatant was decanted. The residual solid was dried under reduced pressure at 92°C, to thereby recover 33.9 g of a polymer U.

[0151] (Example 1)

[0152] A dimethylformamide solution of the copolymer A obtained in Synthesis Example 2, 117.4 g, toluene, 117.4 g, 37 mass% formalin, 31.1 g, and 28 mass% potassium hydroxide aqueous solution, 38.3 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 18.2 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and then dried under reduced pressure at 60°C, whereby 14.2 g of Product 1 was recovered. The Mw of Product 1 was 5500, the styrene ratio was 62.1 mol%, the divinylbenzene ratio was 16.2 mol%, and the acenaphthylene ratio was 21.7 mol%.

[0153] (Example 2)

[0154] A dimethylformamide solution of the copolymer B obtained in Synthesis Example 3, 117.2 g, toluene, 117.2 g, 37 mass% formalin, 37.6 g, and 28 mass% potassium hydroxide aqueous solution, 46.5 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 22.1 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and then dried under reduced pressure at 60°C, whereby 13.0 g of Product 2 was recovered. The Mw of Product 2 was 5400, the styrene ratio was 57.9 mol%, the divinylbenzene ratio was 20.8 mol%, and the acenaphthylene ratio was 21.3 mol%.

[0155] (Example 3)

[0156] A dimethylformamide solution of the copolymer C obtained in Synthesis Example 4, 121.4 g, toluene, 121.4 g, 37 mass% formalin, 23.7 g, and 28 mass% potassium hydroxide aqueous solution, 29.3 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 13.9 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 16.4 g of product 3 was recovered. The Mw of the product 3 was 5500, the styrene ratio was 66.9 mol%, the divinylbenzene ratio was 10.4 mol%, and the acenaphthylene ratio was 22.7 mol%.

[0157] (Example 4)

[0158] A dimethylformamide solution of the copolymer D obtained in Synthesis Example 5, 116.5 g, toluene, 116.5 g, 37 mass% formalin, 31.6 g, and 28 mass% potassium hydroxide aqueous solution, 39.0 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 18.6 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 14.0 g of product 4 was recovered. The Mw of the product 4 was 5700, the styrene ratio was 73.5 mol%, the divinylbenzene ratio was 17.0 mol%, and the acenaphthylene ratio was 9.5 mol%.

[0159] (Example 5)

[0160] A dimethylformamide solution of the copolymer E obtained in Synthesis Example 6, 116.8 g, toluene, 116.8 g, 37 mass% formalin, 30.1 g, and 28 mass% potassium hydroxide aqueous solution, 37.2 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 17.7 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 14.6 g of product 5 was recovered. The Mw of the product 5 was 5100, the styrene ratio was 52.3 mol%, the divinylbenzene ratio was 15.7 mol%, and the acenaphthylene ratio was 32.0 mol%.

[0161] (Example 6)

[0162] A dimethylformamide solution of the copolymer F obtained in Synthesis Example 7, 125.0 g, toluene, 125.0 g, 37 mass% formalin, 24.1 g, and 28 mass% potassium hydroxide aqueous solution, 29.7 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 14.1 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 16.9 g of product 6 was recovered. The Mw of the product 6 was 5200, the styrene ratio was 63.0 mol%, the divinylbenzene ratio was 10.6 mol%, and the acenaphthylene ratio was 26.4 mol%.

[0163] (Example 7)

[0164] A dimethylformamide solution 114.3 g of the copolymer G obtained in Synthesis Example 8, toluene 114.3 g, 37 mass% formalin 37.1 g, and 28 mass% potassium hydroxide aqueous solution 45.9 g were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 21.8 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 12.7 g of the product 7 was recovered. The product 7 had a Mw of 5700, a styrene ratio of 63.5 mol%, a divinylbenzene ratio of 20.8 mol%, and an acenaphthylene ratio of 15.7 mol%.

[0165] (Example 8)

[0166] A dimethylformamide solution 111.9 g of the copolymer H obtained in Synthesis Example 9, toluene 111.9 g, 37 mass% formalin 35.1 g, and 28 mass% potassium hydroxide aqueous solution 43.4 g were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 20.6 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 12.9 g of the product 8 was recovered. The product 8 had a Mw of 6000, a styrene ratio of 49.1 mol%, a divinylbenzene ratio of 20.2 mol%, and an acenaphthylene ratio of 30.7 mol%.

[0167] (Example 9)

[0168] A dimethylformamide solution of the copolymer I obtained in Synthesis Example 10, 123.5 g, toluene, 123.5 g, 37 mass% formalin, 24.9 g, and a 28 mass% potassium hydroxide aqueous solution, 30.7 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 14.6 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 16.6 g of Product 9 was recovered. The Mw of Product 9 was 5100, the styrene ratio was 79.0 mol%, the divinylbenzene ratio was 9.7 mol%, and the acenaphthylene ratio was 11.3 mol%.

[0169] (Example 10)

[0170] A dimethylformamide solution of the copolymer J obtained in Synthesis Example 11, 122.5 g, toluene, 122.5 g, 37 mass% formalin, 28.2 g, and a 28 mass% potassium hydroxide aqueous solution, 34.9 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 16.6 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 15.7 g of Product 10 was recovered. The Mw of Product 10 was 6400, the styrene ratio was 42.9 mol%, the divinylbenzene ratio was 16.8 mol%, the acenaphthylene ratio was 21.9 mol%, and the vinylcyclohexane ratio was 18.4 mol%.

[0171] (Example 11)

[0172] A dimethylformamide solution of the copolymer K obtained in Synthesis Example 12, 120.8 g, toluene, 120.8 g, 37 mass% formalin, 23.7 g, and 28 mass% potassium hydroxide aqueous solution, 29.3 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 13.9 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 16.5 g of Product 11 was recovered. The Mw of Product 11 was 5200, the styrene ratio was 62.7 mol%, the divinylbenzene ratio was 16.0 mol%, and the acenaphthylene ratio was 21.3 mol%.

[0173] (Example 12)

[0174] A dimethylformamide solution of the copolymer L obtained in Synthesis Example 13, 115.7 g, toluene, 115.7 g, 37 mass% formalin, 31.1 g, and 28 mass% potassium hydroxide aqueous solution, 38.3 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 18.2 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 14.3 g of Product 12 was recovered. The Mw of Product 12 was 10900, the styrene ratio was 60.7 mol%, the divinylbenzene ratio was 16.9 mol%, and the acenaphthylene ratio was 22.4 mol%.

[0175] (Example 13)

[0176] A dimethylformamide solution of the copolymer M obtained in Synthesis Example 14, 126.3 g, toluene, 126.3 g, 37 mass% formalin, 23.7 g, and 28 mass% potassium hydroxide aqueous solution, 29.3 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 13.9 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 16.5 g of Product 13 was recovered. The Mw of Product 13 was 2600, the styrene ratio was 64.7 mol%, the divinylbenzene ratio was 15.0 mol%, and the acenaphthylene ratio was 20.3 mol%.

[0177] (Comparative Example 1)

[0178] A dimethylformamide solution of the copolymer N obtained in Comparative Synthesis Example 1, 129.7 g, toluene, 129.7 g, 37 mass% formalin, 36.2 g, and 28 mass% potassium hydroxide aqueous solution, 44.7 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 21.3 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 15.6 g of Product 14 was recovered. The Mw of Product 14 was 5600, the styrene ratio was 83.2 mol%, the divinylbenzene ratio was 16.8 mol%.

[0179] (Comparative Example 2)

[0180] A dimethylformamide solution of the copolymer O obtained in Comparative Synthesis Example 2, 120.1 g, toluene, 120.1 g, 37 mass% formalin, 29.1 g, and a 28 mass% potassium hydroxide aqueous solution, 35.9 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 17.1 g of anhydrous magnesium chloride was charged, and stirring was performed at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, after the solid was removed by filtration, drying was performed under reduced pressure at 60°C, whereby 15.2 g of product 15 was recovered. The Mw of the product 15 was 6000, the styrene ratio was 63.9 mol%, the divinylbenzene ratio was 15.8 mol%, and the vinylcyclohexane ratio was 20.3 mol%.

[0181] (Comparative Example 3)

[0182] A dimethylformamide solution of the copolymer P obtained in Comparative Synthesis Example 3, 116.1 g, toluene, 116.1 g, 37 mass% formalin, 26.9 g, and a 28 mass% potassium hydroxide aqueous solution, 33.1 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 15.8 g of anhydrous magnesium chloride was charged, and stirring was performed at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, after the solid was removed by filtration, drying was performed under reduced pressure at 60°C, whereby 14.9 g of product 16 was recovered. The Mw of the product 16 was 5500, the styrene ratio was 63.2 mol%, the divinylbenzene ratio was 15.7 mol%, and the isobornyl acrylate ratio was 21.1 mol%.

[0183] (Comparative Example 4)

[0184] A dimethylformamide solution of the copolymer Q obtained in Comparative Synthesis Example 4, 130.2 g, toluene, 130.2 g, 37 mass% formalin, 36.3 g, and 28 mass% potassium hydroxide aqueous solution, 44.9 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 21.3 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was removed by filtration, and dried under reduced pressure at 60°C, whereby 15.7 g of product 17 was recovered. The Mw of the product 17 was 6200, the styrene ratio was 84.4 mol%, and the divinylbenzene ratio was 15.6 mol%.

[0185] (Comparative Example 5)

[0186] Styrene, 77.6 g, acenaphthylene, 20.0 g, 2,4-diphenyl-4-methyl-l-pentene, 10.2 g, 2,2'-azobis(2,4,4-trimethylpentane), 3.71 g, and dimethylformamide, 227.6 g, were charged into a 500 mL reactor, and allowed to react at 120°C for 3 hours under nitrogen. The reaction solution was reprecipitated in a large excess of methanol, and then the supernatant was decanted. The residual solid was dried under reduced pressure at 80°C, whereby 58.2 g of product 18 was recovered. The Mw of the product 18 was 4900, the styrene ratio was 76.9 mol%, and the acenaphthylene ratio was 23.1 mol%.

[0187] (Comparative Example 6)

[0188] A dimethylformamide solution of the copolymer R obtained in Comparative Synthesis Example 5, 113.2 g, toluene, 113.2 g, 37 mass% formalin, 24.9 g, and 28 mass% potassium hydroxide aqueous solution, 30.7 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 14.6 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was removed by filtration, and dried under reduced pressure at 60°C, whereby 14.9 g of product 19 was recovered. The Mw of the product 19 was 4700, the divinylbenzene ratio was 13.0 mol%, and the acenaphthylene ratio was 87.0 mol%.

[0189] (Comparative Example 7)

[0190] A dimethylformamide solution of the copolymer S obtained in Comparative Synthesis Example 6, 120.6 g, toluene, 120.6 g, 37 mass% formalin, 29.1 g, and a 28 mass% potassium hydroxide aqueous solution, 35.9 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 17.1 g of anhydrous magnesium chloride was charged, and stirring was performed at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, after the solid was removed by filtration, drying was performed under reduced pressure at 60°C, thereby recovering 15.2 g of product 20. The Mw of the product 20 was 6300, the styrene ratio was 62.1 mol%, the divinylbenzene ratio was 16.5 mol%, and the vinylcyclohexane ratio was 21.4 mol%.

[0191] (Comparative Example 8)

[0192] A dimethylformamide solution of the copolymer T obtained in Comparative Synthesis Example 7, 116.6 g, toluene, 116.6 g, 37 mass% formalin, 26.9 g, and a 28 mass% potassium hydroxide aqueous solution, 33.1 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 15.8 g of anhydrous magnesium chloride was charged, and stirring was performed at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, after the solid was removed by filtration, drying was performed under reduced pressure at 60°C, thereby recovering 15.0 g of product 21. The Mw of the product 21 was 5700, the styrene ratio was 63.8 mol%, the divinylbenzene ratio was 15.5 mol%, and the isobornyl acrylate ratio was 20.7 mol%.

[0193] (Comparative Example 9)

[0194] 5.7 g of the product 17 obtained in Comparative Example 4 and 2.0 g of the polymer U obtained in Comparative Synthesis Example 8 were mixed, and dissolved in toluene to prepare a uniform solution. The solution was dried under reduced pressure at 60°C, thereby recovering 7.3 g of composition 1. The Mw of the composition 1 was 6100, the styrene ratio was 67.5 mol%, the divinylbenzene ratio was 12.5 mol%, and the acenaphthylene ratio was 20.0 mol%.

[0195] The dielectric constant, dielectric loss tangent, glass transition temperature, and melt viscosity were evaluated for the products and compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 9. The results are shown in Tables 1 to 5 below.

[0196] [Table 1]

[0197] Example 1 Example 2 Example 3 Example 4 Example 5 Styrene ratio (mol%) 62.1 57.9 66.9 73.5 52.3 Divinylbenzene ratio (mol%) 16.2 20.8 10.4 17.0 15.7 Acenaphthylene ratio (mol%) 21.7 21.3 22.7 9.5 32.0 Weight average molecular weight Mw 5500 5400 5500 5700 5100 Dielectric constant (10 GHz) A A A A A Dielectric loss tangent (10 GHz) A A A A A Glass transition temperature A A B B A Melt viscosity ○ ○ ○ ○ ○

[0198] [Table 2]

[0199] Example 6 Example 7 Example 8 Example 9 Example 10 Styrene ratio (mol%) 630 63.5 49.1 79.0 42.9 Divinylbenzene ratio (mol%) 10.6 20.8 20.2 9.7 16.8 Acenaphthylene ratio (mol%) 26.4 15.7 30.7 11.3 21.9 Vinylcyclohexane ratio (mol%) - - - - 18.4 Weight average molecular weight Mw 5200 5700 6000 5100 6400 Dielectric constant (10 GHz) A B B B B Dielectric loss tangent (10 GHz) A A A A A Glass transition temperature A A A C A Melt viscosity ○ ○ ○ ○ ○

[0200] [Table 3]

[0201] Example 11 Example 12 Example 13 Styrene ratio (mol%) 62.7 60.7 64.7 Divinylbenzene ratio (mol%) 16.0 16.9 15.0 Acenaphthylene ratio (mol%) 21.3 22.4 20.3 Weight average molecular weight Mw 5200 10900 2600 Dielectric constant (10 GHz) C A A Dielectric loss tangent (10 GHz) C A A Glass transition temperature A A A Melt viscosity ○ ○ ○

[0202] [Table 4]

[0203] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Styrene ratio (mol%) 83.2 63.9 63.2 84.4 76.9 Divinylbenzene ratio (mol%) 16.8 15.8 15.7 15.6 - Acenaphthylene ratio (mol%) - - - - 23.1 Vinylcyclohexane ratio (mol%) - 20.3 - - - Isobornyl acrylate ratio (mol%) - - 21.1 - - Weight average molecular weight Mw 5600 6000 5500 6200 4900 Dielectric constant (10 GHz) D D E A - Dielectric loss tangent (10 GHz) D D E A - Glass transition temperature D D B D - Melt viscosity ○ ○ ○ ○ -

[0204] [Table 5]

[0205] Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) - 62.1 63.8 67.5 Divinylbenzene ratio (mol%) 13.0 16.5 15.5 12.5 Acenaphthylene ratio (mol%) 87.0 - - 20.0 Vinylcyclohexane ratio (mol%) - 21.4 - - Isobornyl acrylate ratio (mol%) - - 20.7 - Weight average molecular weight Mw 4700 6300 5700 6100 Dielectric constant (10 GHz) A B D B Dielectric loss tangent (10 GHz) A A D A Glass transition temperature A D B D Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Acenaphthylene ratio (mol%) Vinylcyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight M × ○ ○ ×

[0206] Example 11 and Comparative Examples 1 to 3 are examples in which a peroxide type polymerization initiator is used. Since acenaphthylene units are not present in Comparative Example 1, the glass transition temperature is poor. In Comparative Example 2, vinylcyclohexane is added as a monomer to be copolymerized in addition to Comparative Example 1, but the glass transition temperature is not improved. In Comparative Example 3, isobornyl acrylate is added as a monomer to be copolymerized in addition to Comparative Example 1, the glass transition temperature is improved, but the dielectric constant and dielectric loss tangent are both deteriorated due to the presence of an ester group.

[0207] In contrast, in Example 11, by incorporating acenaphthylene units in addition to Comparative Example 1, the dielectric constant and dielectric loss tangent are somewhat improved, and the glass transition temperature is significantly improved, so that both the dielectric properties and the glass transition temperature can be taken into account. In Example 11, moreover, the lowest melt viscosity is also low.

[0208] Examples 1 to 10, Examples 12 to 13, and Comparative Examples 4 to 9 are examples in which the above-described azo initiator of formula (1) is used. In Comparative Example 4, the dielectric properties are improved in addition to Comparative Example 1, but since acenaphthylene units are not present, the glass transition temperature is poor as in Comparative Example 1.

[0209] In Comparative Example 5, no divinylbenzene units are present, and no heat curing is performed. Therefore, a test piece for evaluation of the dielectric constant, dielectric loss tangent, and glass transition temperature cannot be produced, and evaluation of these items cannot be performed. In addition, since no heat curing is performed, the melt viscosity monotonously decreases, so that the lowest melt viscosity cannot be observed.

[0210] In Comparative Example 6, the dielectric properties and the glass transition temperature are excellent, but the lowest melt viscosity is high and the processability is poor because the styrene unit is not contained. In Comparative Example 7, vinylcyclohexane is added as a monomer to be copolymerized in addition to Comparative Example 4, but the glass transition temperature is not improved. In Comparative Example 8, isobornyl acrylate is added as a monomer to be copolymerized in addition to Comparative Example 4, and the glass transition temperature is improved, but the dielectric constant and the dielectric loss tangent are deteriorated due to the presence of the ester group.

[0211] In Comparative Example 9, the product 17 of Comparative Example 4 is mixed with the polymer U which is acenaphthylene homopolymer, and contains styrene units, divinylbenzene units, and acenaphthylene units as the components, but the glass transition temperature is poor and the lowest melt viscosity is high, and the processability is poor.

[0212] On the other hand, in Examples 1 to 10, and Examples 12 to 13, the glass transition temperature is excellent while the dielectric constant and the dielectric loss tangent are substantially maintained excellent by incorporating the acenaphthylene unit, and thus the dielectric properties and the glass transition temperature can be balanced. In addition, the lowest melt viscosity is also low.

[0213] In addition, in the products of Examples 1 to 13, even if a thermoplastic resin or a crosslinking agent is not used, a sheet which is sufficient to be self-standing can be formed, and the formability is excellent.

[0214] Further, as for the various numerical ranges described in the specification, the upper limit value and the lower limit value of each of these can be combined arbitrarily, and all of these combinations are described as preferred numerical ranges in the present specification. In addition, the description of the numerical range of "X to Y" means X or more and Y or less.

[0215] The above describes several embodiments of the present application, but these embodiments are suggested as examples and are not intended to limit the scope of the application. These embodiments can be implemented in various ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the application. These embodiments or omissions, substitutions, and changes, and the like are included in the scope or spirit of the application, and are included in the scope of the application described in the claims and the equivalent scope thereof.

Claims

1. A thermosetting resin characterized by comprising: the thermosetting resin is a linear copolymer, and has a repeating unit corresponding to a monovinyl aromatic compound, a repeating unit corresponding to a divinyl aromatic compound, and a repeating unit corresponding to an aromatic ring-condensed cyclic olefin compound.

2. The thermosetting resin according to claim 1, wherein the content of the repeating unit corresponding to the aromatic ring-condensed cyclic olefin compound is 5 to 80 mol% in 100 mol% of the total repeating units.

3. The thermosetting resin according to claim 1, wherein at the terminal of the straight-chain copolymer, R 1 -N=N-R 2 represents the structure of a polymerization initiator, R 1 and R 2 each independently represents a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group.

4. The thermosetting resin according to claim 1, wherein the total content of the repeating unit corresponding to the monovinyl aromatic compound, the repeating unit corresponding to the divinyl aromatic compound, and the repeating unit corresponding to the aromatic ring-condensed cyclic olefin compound is 80 mol% or more in 100 mol% of the total repeating units.

5. The thermosetting resin according to claim 1, wherein the number of rings of the aromatic ring-condensed cyclic olefin compound is 3 or less.

6. A cured product characterized by being cured from the thermosetting resin according to any one of claims 1 to 5.

7. A thermosetting composition characterized by comprising the thermosetting resin according to any one of claims 1 to 5.

8. The thermosetting composition according to claim 7, wherein the thermosetting composition is a printed board material. ​ ​

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